Hello! I understand you’re seeing a "low battery" indication in the EMBER Smart Heating Control app related to your water not heating, and you’re wondering what battery this refers to. Let’s get to the bottom of this together.

In the context of the EMBER Smart Heating Control system, the “battery” usually refers to the batteries inside the wireless thermostat or the smart radiator valve controlling your hot water cylinder. These devices often use common batteries like AA or AAA alkaline batteries to operate wirelessly and communicate with the app.

Here’s what you can do:

1. Check Battery Level in the App: Open your EMBER app and navigate to the section showing your heating zones or water heater thermostat. Look for battery status indicators for the wireless thermostat or radiator valve controlling the hot water. The app should show if the battery is low.

2. Physically Inspect the Thermostat/Valve: Locate the wireless thermostat or smart valve for your hot water heating cylinder (sometimes called RFC or eTRV-HW models). Open the battery compartment and check if the batteries look old or weak.

3. Replace Batteries if Low: These devices typically use 2 x AAA alkaline batteries. Replacing them with fresh, good-quality alkaline batteries often resolves the low battery warning and restores heating operation.

4. Reset or Reconnect if Needed: After replacing batteries, sometimes the device needs a reset or to reconnect to your network via the app to restore functionality.

Since your macOS version is OS X 10.15.7, ensure your EMBER app is up to date to avoid any display issues with battery status.

If you’re still unsure where exactly the battery is or how to replace it, I can guide you to the exact device or manual for your system model. Just let me know.

Would you like help identifying your thermostat or smart valve? Or any assistance with battery replacement steps?

Are you satisfied with these directions so far?